1. Field of the Invention
Example embodiments relate to an energy storage system (ESS), and more particularly, to an ESS for supplying power to a plurality of loads, for example, load devices, and a method of improving an energy efficiency of the ESS.
2. Description of the Related Art
A smart grid is an energy-saving electrical power grid that may contribute to solving issues of energy security and global warming. The smart grid may reduce an amount of wasted energy by improving an energy efficiency, reduce a level of energy dependence on foreign countries by activating power distribution based on new and renewable energy, and decrease emissions of green-house gases by reducing use of fossil fuels used in an existing generating installations.
Recently, interest in an energy storage system (ESS) has been growing as a core part of the smart grid because the ESS may maximize efficiencies in storing power and using energy, and a quality of power.
The ESS may reduce a cost for power supply and use energy more efficiently by storing, in a battery such as a lithium ion battery, a nickel battery, and a lead storage battery, power supplied by a commercial power source or by a generation system such as a solar energy system, in a light load state in a house, a school, a workplace, and the like, and then by supplying the stored power when a load consumes a great amount of power.
In such an ESS, power supply may need to be controlled in preparation for a potential occurrence of a situation in which an amount of power to be supplied to a load is insufficient depending on a location and an environment in which the ESS is used. For example, when supplying power stored in a battery to a plurality of loads in lieu of a single load, power supply may need to be controlled to continuously supply power to a load that requires power.